I want to use numbers as a Header when Inserting a Table.

Before starting the basic sheet, I turned off "Enable Autocomplete" in "Advanced options\Editing options".

The numbers in horizontal order were: 5, 2, 15, 15, 1, 2, 6, 1, 3, 40.

When I Inserted a Table, I "checked" to make these numbers the Header Row.

They immediately changed to: 5, 2, 15, 152, 1, 23, 6, 14, 3, 40 (my bold).

There seems to be a little pattern here in that the extra digits are 2, 3, 4, but why?

The only way to trick it out of this was to place a " either before or after the number, and then disguise the " by making it the same colour as the cell.

Does Excel not like simple numbers as Headers? Was there another way to avoid this issue?

Many thanks.